1. Field of the Invention
The present invention relates to an opening-closing guiding structure of a long-stroke sliding cover, and in particular relates to a sliding-cover guiding structure providing a labor-saving way to open a sliding cover and enabling the rest opening sliding stroke to be automatically performed.
2. Description of the Related Art
Referring to FIGS. 1, 2, 3 and 4, a conventional sliding-cover structure device, capable of being suitable for large-sized electronic products and provided with enforced driving elasticity, mainly includes an upper cover 51 and at least one elastic element 53. The upper cover 51 formed with an U-shaped profile includes a top surface, longitudinal sliding slots 54 disposed on the top surface, and lateral long slots 512. The elastic element 53 includes a fixed end 532 and a free end 531, wherein the fixed end 532 is utilized to be fixed at near the side end of the lateral long slot 512 of the upper cover 51, and the free end 531 connectively installed with a sliding-rolling element 533 which is slidably embedded in the lateral long slot 512 of the upper cover 51 in the direction of the middle section of the lateral long slot 512. The U-shaped upper cover 51 includes two ends respectively extended with folded tabs 510 and two sides formed with concave slots for installing the longitudinal sliding slots 54. The longitudinal sliding slot 54 of the upper cover 51 includes two holes provided at the ends thereof, wherein the two holes are utilized to fixedly receive the fixed ends 532 of the elastic elements 53, respectively.
A bottom plate 52 includes two slide rails 521 disposed on two sides thereof, wherein the two slide rails 521 are embeddable into the longitudinal sliding slots 54 of the upper cover 51. The longitudinal sliding slots 54 of the upper cover 51 are respectively provided with concave slots to be fitted by the two slide rails 521 of the bottom plate 52. Two clamping plate disposed on two ends of the longitudinal sliding slots 54 of the upper cover 51 are utilized to fix on the concave slots of the upper cover 51. The bottom plate 52 further includes two corresponding guide grooves 522 provided with bent-outwardly ends, and the sliding-rolling elements 533 are slidably embedded in the lateral long slots 512 of the upper cover 51 and the guide grooves 522 of the bottom plate 52. At the middle sections of the guide grooves 522 of the bottom plate 52, surpass points 534 and 535 are formed when recurvatures are generated by the guide grooves 522 at different positions, and a cushion portion X is defined by the surpass points 534 and 535. In the operation process, when the sliding-rolling elements 533 are shifted to the cushion portion X in the certain direction, it is necessary that at least the sliding-rolling elements 533 pass through the far surpass point 534 or 535 of the cushion portion X, so that the upper cover 51 is allowed to slidably move in the predetermined direction to automatically complete the sliding stroke in the unfolding or folding process. As a result, in the operation process, it is necessary for a user to move the upper cover 51 for a longer period such that the upper cover 51 can have an automatic sliding effect relative to the bottom plate 52.